This sub-Forum is for posts on the basics of Bonsai, handy tips and other useful ideas to get you started on your own Bonsai. If you are new to Bonsai, read here before posting queries as you may find the answer. Ask questions on the main Bonsai forum and if the answer is of general interest it will end up here.

As I said in part one, bonsai soil should be free draining and that is my maxim for keeping the health of the tree paramount.
I prefer Debco bonsai soil mix because it is pretty inert, less organic. It contains zeolite, a mineral which retains the good nutrients and gets rid of the bad stuff like ammonia. This mix also contains a soil wetter which of course is of benefit in our dry climate. You could use this mix exclusively but I add 50% 1/4 minus crushed granite which loosens up the mix. So that is my basic mix.
However different species require variations like the Azaleas, the acid lovers, they like about 25% of peat moss added. This also goes for the conifers like the Junipers and Pines. For deciduous trees I add about 10% of a good quality potting mix for humus to the basic mix.
I see no problem in growing your trees in just a potting mix in the very short term but eventually they will suffer from from being too wet and incur root rot.
Your comments are welcomed and will be answered.

My Kind Regards Ash

Better to procrastinate than lose sight of the objective by rash deeds

I've read both of the 'Soils ain't Soils' posts and have to agree with everything Ash has said. We can't get Debco potting mix up here so I use Searles Premium to which I add about 30% grit (that I sift out of 'bedding' sand from a local supplier), a pinch of trace elements, chook poo (dynamic lifter or Rooster Booster) and if I have it, some well rotted cow manure. I'm lucky enough to have access to heaps of it from a local dairy - I pick it up by the trailer load. That's my basic mix and for Junipers I also add some very sharp river sand that I have also sifted out of the 'Bedding' sand to make it up to about 50%.
As Ash said, everyone has their own mix so if yours works for you then that's great. A little tip here: be very careful if you use 'Water Crystals'. After a period of time they end up as a very gluggy mess in the bottom of your pots and can make your mix very waterlogged which can result in root rot.

I am new to these forums, and to bonsai also.
I bought a little fig tree from a nursery not too long ago and its looking quite good I think. When I first got it home I put it in a bonsai pot with a little bit of gravel covering the mesh on the bottom and the rest a mix I got from the nursery for bonsai. In the future I want to make my own mix - I read in a cactus book that a soil mix should contain - 3 parts either peat, coconut fibre, or wood bark, and one part washed grit. I thought this could be good for bonsai too, what do you think? Although I did read that you should never use peat for bonsai because it holds too much water and goes too soggy. So I though I might just get 2 parts coconut fibre and/or wood bark and one part small gravel or grit. Does this sound good, should I have a topdressing of small gravel/grit?
Thanks

DamienO'Connor wrote:I am new to these forums, and to bonsai also. I bought a little fig tree from a nursery not too long ago and its looking quite good I think. When I first got it home I put it in a bonsai pot with a little bit of gravel covering the mesh on the bottom and the rest a mix I got from the nursery for bonsai. In the future I want to make my own mix - I read in a cactus book that a soil mix should contain - 3 parts either peat, coconut fibre, or wood bark, and one part washed grit. I thought this could be good for bonsai too, what do you think? Although I did read that you should never use peat for bonsai because it holds too much water and goes too soggy. So I though I might just get 2 parts coconut fibre and/or wood bark and one part small gravel or grit. Does this sound good, should I have a topdressing of small gravel/grit? Thanks

Hi Damien. Welcome to the interesting world of Bonsai.
That mix you are suggesting is a very sterile mix - ideal for cactus that don't require too much in the way of nutrients and water. If you use it on Bonsai though you will need to fertilize every couple of days and there will be a lot of wasted water and fertilizer - and it will dry out very quickly. For Bonsai you need something a bit more substantial that will give you good moisture retention but not give your trees wet feet, and will supply nutrients to the trees for a reasonable length of time.
Every Bonsai 'nut' has their particular favourite when it comes to soil mixes and every book on the subject will give you different information. A lot of the information in books comes about because of the environment and climate in the particular country that the author lives. I've been growing Bonsai since 1989 and in various parts of the country - Darwin, where it is tropical and very humid, Sydney, where it is mainly dry and hot in the summer and sub zero in the winter and now here in Maryborough Qld where it is more sub-tropical, but during the summer can be hot and dry one day and hot and very humid the next.
Whereabouts do you live?
Using 'commercial' Bonsai mix is ok if you only intend to have a very small number of trees, but in my case, if I was to use it I'd need to be a millionaire - I have over 200 in various stages of development, so use quite a bit of mix. Some people just use a good quality potting mix straight out of the bag and they are quite happy with their results.
My 'Basic' mix that I use for most of my trees is as follows:
4 large scoops good quality potting mix (Debco, Searles Premium, Katek for example).
1 large scoop grit (minimum size 3mm) - I buy bedding sand by the cubic metre from a local supplier and sift it out myself. The fine stuff goes into a pile for mixing up mortar or spread around the garden.
1/2 small scoop cow manure.
1/2 small scoop chook pellets (dynamic lifter, rooster booster etc).
1 pinch of trace elements.
For most garden applications a good quality potting mix on it's own is fine, but I prefer to add more fertilizer because for bonsai as I don't think there is enough in a commercial bag of mix - and it means a longer time before I have to fertilize again.
This mix gives good water retention, but is also very free draining, meaning the trees don't get 'wet feet' (fatal to most trees except things like Swamp Cypress, most Casuarinas and other water loving trees).
I modify the mix for different trees such as:
Azaleas which require a more acidic soil mix, I add a small pinch of sulphur.
Junipers (and pines) I add more sand up to 40% sand to 60% potting mix and also add calcium in the form of finely crushed (pulverized) eggshells. Junipers and pines prefer a more alkaline mix and love calcium.
I now have 18 different species of fig - both deciduous and non-deciduous and I would suggest your fig wouldn't do very well in the mix you proposed. Figs need good moisture retention and don't appreciate drying out - they also like a lot of fertilizer.
I use a larger gravel (10mm) as a 'mulch' on the top of my pots to slow down evaporation and I get this from sifting out what is called 'concrete mix'. I can also get the smaller useful grit from this same stuff but not in the quantities available from the bedding sand.
Fertilizer is also a 'personal choice' subject. Some people use purely Slow-release, others natural manures like cow, chook etc and some use a mixture. I personally prefer animal manures but I wouldn't think of telling anyone they were doing wrong using slow-release. Some people have no choice, especially if they live in a unit or a flat. It wouldn't be too good having a bag of chook pellets stored in their kitchen or clothes cupboard A bit of research has been done on the sole use of slow-release with the conclusion that it can lead to a build-up of mineral salts within the soil mix. This can be overcome though by totally dunking the pot every so often in clean water to wash away any salt build-up.
In reality Bonsai isn't too far removed from normal gardening using terracotta or black plastic pots, and plants growing in normal potting mix in those conditions are quite happy. Our main difference is our pots are usually fairly shallow so dry out a lot quicker and therefore need a bit better watering regime.
If you really get into Bonsai you will gradually work out a mix that suits yourself, your climate and most importantly, your trees.
Hope this has been a bit of help to you Damien.

I have just the one fig tree, two cactus and a jade plant, all in pots. I'm new to plants, so I don't know a lot. The cactus are new, so they are in the original black plastic pots and soil. The jade I have in a terracota pot with a cactus mix I bought, with some gravel on the bottom. As I said the fig is in a bonsai mix that I bought, with the gravel on the bottom also. I'm thinking of repotting my fig into a big pot so that it can grow more (it's quite small), because it is in a bonsai pot right now. I still have a lot of gravel (it was given to me) and some of that bonsai mix - I guess I was just thinking about the future when I wanted to make the mix myself, because I want to have lots of plants. At the moment I am using seasol for fertiliser (seaweed fertiliser), but I want to get osmocote also.
Damien.

One word of advice if using osmocote or any other "slow release" type fertilisers - dont spread the pellets on top of the soil, always make a small recess in 2-3 spots,place a small amount of pellets and cover over with the original soil. Most slow release ferts are wasted by the wrong application.

Heres another couple of great regimes for your trees,if you can afford it, spread a good healthy amount of dolomite on top of soil once every year, sweetens the soil by reducing acidity. Stop throwing away your coffee grinds, sprinkle on your garden and trees as it is a great supply of nitrogen.

Hi everyone I just want to make an amendment to my mix. After talking with some well known bonsai artists in the U.S. I will now be adding finely chopped spagnum moss in the mix at re-potting time. I have always used spagnum for layering trees knowing the healing and stimulation qualities it has. Don't use excessive amounts as it may retain too much moisture, just enough to be visible. Make sure it is moist when using it, as like most potting mixes when dry, airborne particles can be inhaled. Apparently it stimulates root growth to healthier levels and therefore gives the whole tree a better start at re-potting. A natural organic supplement.

Ash

Better to procrastinate than lose sight of the objective by rash deeds